With rapid development of communications technologies, a wireless communications technology is widely applied because of advantages such as convenient and quick information transmission and a low cost.
Currently, referring to FIG. 1, a wireless communications network includes user equipment (User Equipment, UE) and a network side device. The UE performs a data service with a network side by using an IP address allocated on the network side to the UE. In the wireless communications network, the network side device includes a packet data network gateway (Packet Data Network Gateway, PDN-GW), a serving gateway (Serving Gateway, SGW), and an evolved node (Evolved Node, eNB). One PDN-GW is superior and connected to multiple SGWs, one SGW is superior and is connected to multiple eNBs, and one eNB serves multiple UEs, so as to form a tree structure (as shown in FIG. 2) that uses the PDN-GW as a root. In addition, to ensure quality of service (Quality of Service, QoS) and implement quality of a differentiated service, and also ensure service continuity and call accessibility when UE is moved, the network side device further includes a mobility management entity (Mobile Management Entity, MME), a policy and charging rules function (Policy and Charging Rule Function, PCRF) entity, and a home subscriber server (Home Subscriber Server, HSS). The MME is configured to control mobility of UE, including service continuity of UE in a radio resource control (Radio Resource Control, RRC) connected state in a moving process and incoming call accessibility of UE in an idle state. The PCRF entity is configured between devices such as the PDN-GW and the eNB to ensure QoS and implement quality of a differentiated service by means of bearer management and resource scheduling management.
It can be learned from a tree structure shown in FIG. 2 that all UEs in the wireless communications network perform a data service by using the following path: UE-eNB-SGW-PDN GW. In a wireless communications network architecture with such a tree structure, a large amount of data aggregates on an SGW-to-PDN-GW link. Consequently, when a network is busy, the SGW-to-PDN-GW link becomes backhaul load and a bottleneck of a processing capability of the wireless communications network. In addition, a hierarchical network architecture of the wireless communications network enlarges a data transmission delay. There is further a risk of paralysis of an entire network caused by a PDN-GW data processing error. Therefore, currently, the wireless communications network cannot meet a requirement of mobile bandwidth for large bandwidth and a low delay.
In conclusion, there are problems of a large data transmission delay and a high risk of network paralysis for the current wireless communications network.